An apparatus of the above stated kind is previously known from SE B 7712710-8corresponds to U.S. Pat. No. 4,174,908. The head is displaced in a direction perpendicular to the plane of the record carrier along a guide rod by means of the drive motor, which is in engagement with a toothed gear rack via a gear wheel coupling. Embodiments of transport devices according to the prior art move the head in a direction perpendicular to the record carrier, but however, present a number of disadvantages. The transfer of motion from the motor to the head commonly exhibits a play and in particular when used for some time. The play results in a less accurate positioning of the head and tends to cause jerkiness in the movement of the head, in particular when changing drive direction for the motor. This results in a distorted text, i.e. due to the fact that the head has a tendency to rise during acceleration and sink during retardation. As an example of one of the appearing distortion types is that the characters exhibit a varying character distance. Furthermore, there maybe a risk that the head is damaged in the case that a sudden rapid adjustment of the head position is needed to avoid a collision with the record carrier or another obstacle. In this case distance controlling system which the apparatus according to the above commonly is equipped with, does not have time to adjust the head position to avoid a collision.